Questions and links to answers:

1. What does ACIP recommend for health care workers?
2. Should health care workers be tested for VZV immunity first?
3. Should health care workers be tested afterwards to be sure immune?
4. How should vaccinated health care workers be managed after exposure to natural varicella?
5. Should health care workers be furloughed if develop rash afterwards?
6. What policies have hospitals developed for managing post-vaccination rash in employees?

Go to other pages of related questions:

• Varicella disease specific
• Vaccine specific
• Storage and handling
• Who should get vaccinated
• Pregnancy related

1. Does ACIP recommend immunization of health care workers?

ACIP recommends that all health care workers ensure that they are immune to varicella, since nosocomial transmission of varicella is well-recognized. Varicella immunization is

particularly recommended for susceptible health care workers who have close contact with persons at high risk for serious complications, including a) premature infants born to susceptible mothers, b) infants who are born at < 28 weeks of gestation or who weigh < 1,000 g at birth (regardless of maternal immune status), c) pregnant women and d) immunocompromised persons.

For more information, visit the following site:
ftp://ftp.cdc.gov/pub/Publications/mmwr/RR/RR4511.pdf

2. Should health care workers be tested for VZV immunity prior to vaccination?

Data available to date indicate that in the health care setting, a positive history of disease is a reliable predictor of positive immune status. Among tested health care workers > 97-99% of those with a positive history had antibodies when tested. Employees who do not have a convincing history of prior varicella should be considered susceptible and serological testing can be offered to determine immune status. Serologic screening of adults with a negative or uncertain history is cost-saving compared with vaccinating all those without a definite history, because 70% to 90% are actually immune when tested. Health care workers from tropical climates are more likely to be susceptible to varicella as adults than persons born in the U.S. For ensuring that Health care workers assigned to high risk patients are immune, hospitals may elect to do serology testing for all such employees irrespective of disease history.

3. Should health care workers be tested after vaccination to ensure that they are immune?

The ACIP does not recommend routine testing for varicella immunity after two doses of vaccine because 99% of adults seroconvert after two doses of vaccine. Additionally, there are difficulties interpreting negative lab tests post-vaccination since commercially available tests may not be sensitive enough to detect low levels of antibody post-vaccination. For institutions that choose to do post-vaccination testing, it is suggested that if EIA tests are used for initial screening post-vaccination, then further tests should be conducted on those with negative results using a more sensitive test (e.g.FAMA (flourescent antibody-to-membrane antigen), latex agglutination).

4. How should vaccinated health care workers be managed after exposure to natural varicella?

Hospitals should develop guidelines for management of vaccinated health care workers who are exposed to varicella. Seroconversion after varicella vaccination does not always result in full protection against disease. Therefore, the following measures should be considered for health care workers who are exposed to natural varicella: a) serological testing for varicella antibody immediately after VZV exposure; b) retesting 5-6 days later to determine if an anamnestic response is present; and c) possible furlough or re-assignment of personnel who do not have detectable antibody.

5. Should health care workers be furloughed if they develop a rash after vaccination?

ACIP suggests that hospitals develop their own policies for managing rash post-vaccination. Uncontrolled trials suggest that approximately 3% of adults develop a varicella-like rash (with a median of 2 lesions) at the injection site, and approximately 5.5% develop a generalized rash (median 5 lesions) 2-6 weeks following the first dose of vaccine. The risk of any rash is much lower after the second dose (<1%). The rash may be atypical for varicella with macules or papules rather than vesicles. Health care workers who develop a rash should be evaluated by the occupational health service at the hospital or medical facility where they work and managed according to hospital policy.

6. What policies have hospitals developed for managing post-vaccination rash in employees?

Two large university hospitals (Columbia Presbyterian Medical Center in New York City and Stanford University Hospital in Palo Alto) have instituted the following policy: a) Employees are instructed that they may develop a rash 2-6 weeks after vaccination and that this rash may be either a localized rash at the site of vaccination or a diffuse varicella-like rash. Either rash may be atypical with macules or papules rather than vesicles. Employees are instructed to report immediately to the occupational health office if a rash develops. b) Employees with either an injection site rash or a generalized rash are furloughed until the rash resolves (usually in 2-3 days). The occupational health office verifies that the rash has resolved and they are not potentially infectious to others before allowing the employee to resume patient care duties.

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